Replace string comparing to enum comparing.

Source/modules/webaudio/PannerNode.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 109 matching lines @@
 
     AudioBus* source = input(0)->bus();
     if (!source) {
         destination->zero();
         return;
     }
 
     // The audio thread can't block on this lock, so we call tryLock() instead.
     MutexTryLocker tryLocker(m_processLock);
     if (tryLocker.locked()) {
-        // HRTFDatabase should be loaded before proceeding for offline audio context when panningModel() is "HRTF".
-        if (panningModel() == "HRTF" && !m_hrtfDatabaseLoader->isLoaded()) {
+        // HRTFDatabase should be loaded before proceeding for offline audio context when the panning model is HRTF.
+        if (m_panningModel == HRTF && !m_hrtfDatabaseLoader->isLoaded()) {
             if (context()->isOfflineContext()) {
                 m_hrtfDatabaseLoader->waitForLoaderThreadCompletion();
             } else {
                 destination->zero();
                 return;
             }
         }
 
         // Apply the panning effect.
         double azimuth;
@@ skipping 418 matching lines @@
     ASSERT(context()->isAudioThread());
 
     m_cachedPosition = m_position;
     m_cachedOrientation = m_orientation;
     m_cachedVelocity = m_velocity;
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)